2 * RAM Oops/Panic logger
4 * Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com>
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * version 2 as published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
22 #include <linux/kernel.h>
23 #include <linux/module.h>
24 #include <linux/kmsg_dump.h>
25 #include <linux/time.h>
27 #include <linux/ioport.h>
28 #include <linux/platform_device.h>
29 #include <linux/ramoops.h>
31 #define RAMOOPS_KERNMSG_HDR "===="
33 #define RECORD_SIZE 4096
35 static ulong mem_address
;
36 module_param(mem_address
, ulong
, 0400);
37 MODULE_PARM_DESC(mem_address
,
38 "start of reserved RAM used to store oops/panic logs");
40 static ulong mem_size
;
41 module_param(mem_size
, ulong
, 0400);
42 MODULE_PARM_DESC(mem_size
,
43 "size of reserved RAM used to store oops/panic logs");
45 static int dump_oops
= 1;
46 module_param(dump_oops
, int, 0600);
47 MODULE_PARM_DESC(dump_oops
,
48 "set to 1 to dump oopses, 0 to only dump panics (default 1)");
50 static struct ramoops_context
{
51 struct kmsg_dumper dump
;
53 phys_addr_t phys_addr
;
59 static void ramoops_do_dump(struct kmsg_dumper
*dumper
,
60 enum kmsg_dump_reason reason
, const char *s1
, unsigned long l1
,
61 const char *s2
, unsigned long l2
)
63 struct ramoops_context
*cxt
= container_of(dumper
,
64 struct ramoops_context
, dump
);
65 unsigned long s1_start
, s2_start
;
66 unsigned long l1_cpy
, l2_cpy
;
69 struct timeval timestamp
;
71 /* Only dump oopses if dump_oops is set */
72 if (reason
== KMSG_DUMP_OOPS
&& !dump_oops
)
75 buf
= (char *)(cxt
->virt_addr
+ (cxt
->count
* RECORD_SIZE
));
78 memset(buf
, '\0', RECORD_SIZE
);
79 res
= sprintf(buf
, "%s", RAMOOPS_KERNMSG_HDR
);
81 do_gettimeofday(×tamp
);
82 res
= sprintf(buf
, "%lu.%lu\n", (long)timestamp
.tv_sec
, (long)timestamp
.tv_usec
);
85 hdr_size
= buf
- buf_orig
;
86 l2_cpy
= min(l2
, (unsigned long)(RECORD_SIZE
- hdr_size
));
87 l1_cpy
= min(l1
, (unsigned long)(RECORD_SIZE
- hdr_size
) - l2_cpy
);
89 s2_start
= l2
- l2_cpy
;
90 s1_start
= l1
- l1_cpy
;
92 memcpy(buf
, s1
+ s1_start
, l1_cpy
);
93 memcpy(buf
+ l1_cpy
, s2
+ s2_start
, l2_cpy
);
95 cxt
->count
= (cxt
->count
+ 1) % cxt
->max_count
;
98 static int __init
ramoops_probe(struct platform_device
*pdev
)
100 struct ramoops_platform_data
*pdata
= pdev
->dev
.platform_data
;
101 struct ramoops_context
*cxt
= &oops_cxt
;
105 mem_size
= pdata
->mem_size
;
106 mem_address
= pdata
->mem_address
;
110 printk(KERN_ERR
"ramoops: invalid size specification");
114 rounddown_pow_of_two(mem_size
);
116 if (mem_size
< RECORD_SIZE
) {
117 printk(KERN_ERR
"ramoops: size too small");
121 cxt
->max_count
= mem_size
/ RECORD_SIZE
;
123 cxt
->size
= mem_size
;
124 cxt
->phys_addr
= mem_address
;
126 if (!request_mem_region(cxt
->phys_addr
, cxt
->size
, "ramoops")) {
127 printk(KERN_ERR
"ramoops: request mem region failed");
132 cxt
->virt_addr
= ioremap(cxt
->phys_addr
, cxt
->size
);
133 if (!cxt
->virt_addr
) {
134 printk(KERN_ERR
"ramoops: ioremap failed");
138 cxt
->dump
.dump
= ramoops_do_dump
;
139 err
= kmsg_dump_register(&cxt
->dump
);
141 printk(KERN_ERR
"ramoops: registering kmsg dumper failed");
148 iounmap(cxt
->virt_addr
);
150 release_mem_region(cxt
->phys_addr
, cxt
->size
);
155 static int __exit
ramoops_remove(struct platform_device
*pdev
)
157 struct ramoops_context
*cxt
= &oops_cxt
;
159 if (kmsg_dump_unregister(&cxt
->dump
) < 0)
160 printk(KERN_WARNING
"ramoops: could not unregister kmsg_dumper");
162 iounmap(cxt
->virt_addr
);
163 release_mem_region(cxt
->phys_addr
, cxt
->size
);
167 static struct platform_driver ramoops_driver
= {
168 .remove
= __exit_p(ramoops_remove
),
171 .owner
= THIS_MODULE
,
175 static int __init
ramoops_init(void)
177 return platform_driver_probe(&ramoops_driver
, ramoops_probe
);
180 static void __exit
ramoops_exit(void)
182 platform_driver_unregister(&ramoops_driver
);
185 module_init(ramoops_init
);
186 module_exit(ramoops_exit
);
188 MODULE_LICENSE("GPL");
189 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
190 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");